Georges St-Pierre successfully defended his UFC Welterweight Championship Saturday night at UFC 100 by beating Thiago Alves. St-Pierre retained his title for the third straight time and now faces the question on whether to move up a weight class.

Georges St. Pierre wants to leave a legacy in mixed martial arts, but after his latest victory Saturday night the UFC welterweight champ may be running out of room to improve.

Despite a severely injured groin or abductor muscle, the popular Canadian fighter dominated the division’s top contender — scoring a lop-sided unanimous decision victory over Thiago Alves at UFC 100 at Mandalay Bay.

Even the judge’s scores (50-45, 50-44, 50-45) couldn’t describe how flawlessly “GSP” executed his Greg Jackson-constructed game plan that featured plenty of ground work.

“Thiago Alves was my toughest opponent so far,” said St. Pierre, who improved to 19-2 in MMA and picked up his 14th win in the Octagon — tying him with Randy Couture for the fourth most victories.

“He’s very young (25). This happened to me when I lost to Matt Hughes.”

St. Pierre was 23 when he lost in his first title shot.

But the way the 28-year-old is cruising right now, it seems few legitimate challengers remain in the 170-pound division.

Since losing his title to Matt Serra in April 2007, St. Pierre has lost only one round on the judge’s scorecards in six bouts.

“It's a question of timing," St. Pierre said of the possibility. "I walk around at 185 pounds. I am not that big for a welterweight either. … So if I move up, like I said, I don't fight to be champion anymore because I am a champion.

“If I do it, it's for a challenge, but I am going to have to take the time to gain weight and really take care of business."

St. Pierre did that Saturday, even if business was a bit broken.

The champ could tell immediately in the third that something wasn’t right because he’s suffered a similar injury in the past.

“It’s pretty bad,” he said. “I’m in real bad pain. I realized it when I was on the bottom and I heard my groin and abductor snap.”

But when St. Pierre informed his corner of the possible tear before the final round, he was greeted with little sympathy.

“Well then go out there and hit him with it,” Jackson yelled at him.

Despite not having a competitive past in wrestling, St. Pierre has proved to be one of the most dominating in the sport. Saturday he slammed Alves nearly a dozen times, a strategy that allowed him to avoid the Brazilian's dangerous strikes.

The fact that St. Pierre made the win look so easy, despite the critical injury seems to suggest the legacy “GSP” was hoping to leave is already being recorded for posterity.

“I said if he gets through this one, he’s in the running for the best pound-for-pound fighter in the world,” White said.

“Georges St. Pierre is an amazing human being, an amazing fighter and an amazing athlete. I can’t say enough good things about him.”

Demetrious "Mighty Mouse" Johnson slammed his hands down on his UFC flyweight championship belt. Somewhere else in Rogers Arena, Rory MacDonald surely looked on with envy. Johnson and MacDonald put on dominant performances in the UFC's first trip to Vancouver in three years. Johnson defended his title for the fourth time, not allowing Ali Bagautinov to win any of their five fast-paced rounds. That couldn't quite top MacDonald, who barely let Tyron Woodley touch him in an all-important welterweight co-main event. MacDonald hopes the performance leads him to an opportunity to claim space alongside Johnson in the UFC champion's club.